i've solved the problem with my own searches on internet, writing down if anybody needed in the future;
1-)connect to zentyal through Putty
2-) get root (sudo su)
3-) pico /usr/share/zentyal/stubs/squid/squid-external.conf.mas
4-) find lines starting with acl Safe_ports (in pico to find string use ctrl+w)
5-) if the address working over HTTPS add acl SSL_ports port your_port #explanation
if address working over HTTP add acl Safe_ports port your_port # explanation
6-) Save and exit with ctrl+x
7-) restart squid with "service zentyal squid restart"
you are done.
Also Thanks to Zentyal engineers for not helping with this issue, as allways google is the best.